Camper Water System Upgrades (T2499)

[JohnB]

Yup, Hutch nailed it.

Us folks on 30 amp services have to watch how many devices we have on at one time.

Let’s look. Let’s talk watts first.

1,400 watts. Hot water heater on electric
325 watts. Fridge element when on electric.
Est. 50watts. The power converter over head when not many lights are on. Get’s worse when many lights are on or charging the house battery.
288 watts AC unit fan blowing.
1461 watts AC compressor when running, a 13,500 BTU model. Same one used in my T2499 as in a 32 footer.
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3,524 watts Total steady draw

On 110 volts = 32 amps
On 115 volts =30.6 amps
On 120 volts = 29.4 amps
On 125 volts =28.2 amps.

This is in a constant draw situation. The AC compressor is the killer. It has a locked rotor current of 60 amps. Meaning when it starts a real large spike comes until it is up and running then it drops to 12.7 amps. This is why they state they have to be plugged into a 20 amp service for just a AC unit.

So if the odds all add up when all are on, it does not take much to trip the 30 amp main.

This can also be the same problem even if the AC is not on. Add a 1500 watt hair dryer or a 1300# toaster, at the same time the coffee pot is perking. The micro wave is up to 1500 watts too. I keep explaining this to DW, do not use 2 large heat producing things at the same time. A 1500 watt hair dryer along with a 1500 watt electric heater in the winter can take the camper with the other overhead running.

So watch your watts…..

John

[PTHutch]

JohnB,

Good explanation. Thanks for putting it into more practical terms.

Hutch

[Dave]

Many great ideas for me to consider for next year while hanging around a campground. I have trouble just loungeing around drinking coffee or 'adult' beverages. Of all of the mods, the only one that I would not do is put any kind of permanent or semi permanent attachment to the hot water heater safety blow off valve. They are designed to pass a certain flow and a restriction might hinder the safe operation of that device.

Great quality workmanship

[JohnB]

Dave

Thanks for the comments.

And I fully agree with you on the safety relief valve vent line that that line has to be considered before doing anything to it. If one is not into figuring things out with rated capacities, then best to leave things alone and deal with the issues of not directing the blow off.

In contrast, attaching a vent line on a safety relief valve when done correctly is done every day in industry and in the home. If you happen to have a hot water heater in your basement, it has a vent line to direct the water to the floor as the relief is generally in the top of a vertical tank. If you have a oil fired or gas for that matter, water boiler furnace, it too has a vent line on the safety relief to direct the water to a safe area for blow off.

At work we have 4”, 6” and even 8” steam relief’s, compressed air, and water valves that have vents lines on them to direct the blow off. Most go up thru the roof to direct the blow off. They have to be sized properly to pass the full CFM, lb’s per hour, GPM etc the device is rated for and for the pressure drop of the piping you attach to it.

However most homeowner are not into this type stuff and rightfully so. In the RV setting the issue we face with the relief valve are the drips that come from it and what the drips come in contact with. I would gladly pay Attwood an extra $10 or other reasonably price to have them install something better then the plastic thread protector they put in the vent line to redirect the vent to different area and not eat up the rest of the heater from corrosion.

Now back to the drips. First, where to the drips go. In my case, right down on top of the thermostats and the gas valve. Corrosion will set in on those components faster if you have a leaking relief valve.

Now how does the valve leak? Here are 2 causes I know of that are fairly common with the camper setup.

Cause 1. Thermal expansion. Direct from the factory there is no expansion tank on most campers. When you fill an empty your HW heater an air pocket forms in the top. This air pocket creates an expansion zone so when the water is heated, the expanding water has somewhere to go. For folks who do not drain their HW heater between trips or those that leave the heater on a real long time, days worth, that air pocket can get lost. Now you have no air pocket and a fully filled tank. When the water heats it expands and has to go somewhere. The thermal expansion relives at the safety relieve valve, very slowly and burp/seep and burp/seep it goes. It only burps or seeps enough to relive that quick little pressure and then builds up again.

For me, I turn the HW heater off when I do not need it and I drain the HW heater after every camping trip and blow out the residual water. The air pocket reforms every time and the heat expansion is very limited since the water is only heated for need since I turn it off. The insulation keeps the water and tank farily hot so recovery is quick. Plus I get ride of some of the bad things come from inside your HW heater from just heating water. I also drain for water quality issues but that is another post.

Cause 2. Contamination or corrosion in the valve seat. For folks who do not frequently drain the camper HW heater, calcium and dirt builds up in side. Also incoming water dirt collects in the bottom if they do not filter the water. Granted baked on calcium is everywhere but it also creates little hard particles that clog up sink faucets or any other openings letting water flow out of it with small orifices. How much dirt depends on your water hardness and incoming water quality.

However the contamination was generated, it can find it’s way to seep out the relief when cause 1 occurs. Once the dirt is in the seat, it will not shut up and small drips again come from this. A lifting of the lever under cold conditions will most times dislodge the dirt and it will seal back up. If you have corrosion in the seat, rebuild or replace is about the only way to stop the leak.

Others may have more to this, but this is what I have found from my experiences.

Also slightly off topic, your TV caught my eye. I’m researching one just like it, just the super cab in place of the crew cab. How do you like it? Do you have the 4.30 rear end?

Thanks

John

[Dave]

Hi John,
First off, my discussion about hot water heater safety blow offs was not intended to downplay your modification. I am all to well aware of flows and the restrictions placed on these safety devices after many years of building power plants for a living. Without a calculation of flows, feel that a restriction such as what appears to be a low temperature water hose might compromise safe operation. I would have to plumb that device with some sort of steel pipe after I was sure it was capable of handling the flow.

I do have a piece of piping on my home HW heater to direct it to the floor but it is a 3/4" close nipple into a 3/4 x 1 coupling, another 1" nipple to take it past the tank top, a 1" ell, then another piece to within a foot of the floor.

Unfortunately, my HW heater suffered from the "drips" until I replaced the valve and is coated with lime deposits that are resisting my efforts for a good cleanup. I purchased the trailer used from an individual that turned it on when he arrived and left it on the entire time he used the trailer. We turn it on, use it for dishes, wash up or whatever, then it is turned off. It still works fine - but my guess is that I'll possibly need to replace the unit in the next year or so.

My tow vehicle, an '06 Ford F350 Lariat. I love it. I probably should have purchased another Super Cab but the dealer made me such a deal.....

I purchased the gas V10, 6.8 for several reasons. The PSD diesel that Ford was using thru '04 had more then enough problems, though mostly fixed by the '05 models and since it is my daily driver, felt that I didn't need to spend my retirement arguing with the dealeship and waiting for parts to appear. Secondly, the price of diesel fuel has gone out of sight in my area - $.40 to $.75 higher then gas. Compared to the '08 Ford with the 6.4, I might be giving up 1-2 mpg but the difference in the price of fuel has closed that gap economically. Thirdly, costs of maintenance for a daily driver every 5K miles with 15 quarts of Mobil 1 vs my 7, $70 worth of filters vs my $4.00 . Fourth and most important, an $8800 difference in purchase price over my V10. $52,000+ for a diesel pickup truck was just too much!!!

I bought it with 4.10 gears - the truck pulls my 28 foot 7000+pound Sunline effortlessly through the NY Adirondack mountains at 10mpg.

Now, off to replace my dead water pump so I can finish winterizing my camper.

[Hematite]

Dave: I agree with your analysis of gas vs. diesel. For my situation, as well, gas was the way to go. I went with the F150 because it was adequate for towing the 2499 and I got the Flex Fuel 5.4 engine. Now I'm looking at buying a still and buying local farm crop waste and making my own .30 per gallon Ethanol.

[JohnB]

Hi Dave

Wish we where in a camp site and yaking around the camp fire. First just to have more camping in and second to exchange thoughts on the vent line. If the vent was not on top of the electric components and the system so prone to working level leaks I would not have such an issue with this. But that is not the way it is made.

It appears we both come from and industrial back ground using these in industry. I my case it is using power piping and Section VIII unfired pressure vessels in food sterilization machinery. If you are into fired vessels the rules are different but have a lot of commonality. The reg’s there are cut and dried on the industrial settings for flows and yes we always use hard metal pipe on the steam, air and water systems. On chemical corrosive systems heavy wall plastic (Sch 80 etc) has been used at time due to the environment.

From your thoughts I must admit I’m thinking more on this and may regroup if I can convince myself I messed up. It won’t be the first time nor the last.

As far as temperature and pressure goes, the hose and fittings I have used are rated 150 psi as I checked for that and it is stamped on the hose. On the fittings and temperature they are in the 275F range and 150 psi rated. That I know I checked that too. Now to having be hard pipe, that one I have not run into in the camper setting and may have a miss there. In the industrial arena, it just does not present itself as rigid, verse flex.. It’s rigid for other reasons.

In our campers the plastic semi flex pipes and fittings coming and going from the HW heater have issues if your pressures are much above 50 psi. Leaks at the fittings can come in short order when you climb up into the 60# area. They themselves are relief’s in a practical sense but cannot be claimed in the actual relief valve sizing. When I upgraded my water pump to a variable speed unit it even cautioned to check for leaks as it is a higher pressure pump. The nylon drain plug Atwood installs most likely is 150 psi rated as that is not that hard to come by.

Thinking thru this, if we apply the industrial sizing rules, as those are what we are use to, the relief must relieve all incoming energy to below the vessel working pressure. Which would come if the electric was stuck on and so was the propane at the same time along with the water pump jamming in more pressure. I do not know if the camper industry takes it that far, but on Section VIII vessels we do. I’ll have to go re read the label on the tag of the relief valve. I thought it said 150psi and 212 deg F. The thermal rating will trip at the 212 but the thermal expansion could be a lot higher then the little bit of pressure at 212.

Like I said you have me thinking on this, I will have to check more and report back and correct accordingly if needed. As far as the hard pipe verses flex, have you seen that in a camper setting regulation?

The valve is behind the outside heater door so the exhaust pressure is shielded from spraying all over. So they are most likely are not required to direct the exhaust to a more non hazardous area. Thus stopping short with no vent line and not enough profit margin to design one in away from the electrical and gas components.

On the TV, yes I’m approaching the same conclusion on the new Ford Diesel if I go Ford which was the notice on your V10.. In the GM line, the 3500 SRW truck only comes crew cab long bed and finding an 8.1 is not easy. Everyone is after the Dmax. I’m after crew cab short bed and they do not offer that combo. So my search continues.

Happy camping

John